A database usually includes an interface system that allows a user and/or administrator to access, manage and maintain the database. A common interface used is a database management system (DMS). This interface provides many capabilities such as collecting statistics of the functions of the database.
However, this collection is performed on a global level. The collected information includes only global statistics. A conventional interface observes global level statistics. This mechanism allows viewing statistics only when the execution terminates, not while the statement is running. Also, these statistics are very expensive to collect by default and do not include fine grain timing information such as how much time a plan step spent on CPU or waiting for inputs and outputs (IOs).